An account in Hauts-de-Seine, France

On September 29, 2009 at 3:00 PM, a witness observed through a window the blinking of a small white luminous shape at high altitude. After one minute, the luminous point stopped moving, then resumed its trajectory but without any blinking. According to information gathered by phone from the witness, he was looking toward the South, and the object was moving toward the East (see map). Ground weather readings mention at 2:00 PM a northwest wind, then north at 3:00 PM. The observation therefore does not match an object carried by the wind at low altitude. On the other hand, Météo-France releases weather balloons daily from Trappes around 12:00 UTC, which is 2:00 PM local time, that is, one hour before the observation (see the reading which indicates that the ground wind is NW, fairly weak (5 kt) at 2:00 PM, then shifts to W, stronger (25 kt) from 2800 m, then back to NW higher up). Since the winds at altitude were blowing toward the East, this balloon would explain the observation well, about one hour after release. The blinking corresponds to the rotation of the balloon or of reflectors. GEIPAN classifies this case "A" as identified by the observation of a Météo France weather balloon launched from Trappes at 2:00 PM.